SPSS NPAR Test Warning: insufficient workspace memory

I am attempting to run a Mann-Whitney U test using SPSS but am receiving the following warning message: 'There is insufficient workspace memory to process all the cases. Break up the request, rerun with more workspace, or use the SAMPLE subcommand. You can increase workspace with the SET WORKSPACE command.' I have used the workspace command to increase my workspace to 20000 but am still receiving the error message. The request is too small to break up and my dataset only has 335 participants. All other tests are working (descriptives, ANCOVA etc). How can I run the Mann-Whitney U test?

1 reply

@KimAna
I do not know which SPSS version you use on which exact operating system with which hardware specifications?

For example, I use SPSS Statistics 25 64 bit on Windows 10 Enterprise 64 bit, and the computer has 32 GB RAM.I run below sample syntax for Employee Data.sav, this file has 474 cases.I run the newer NPTESTS where I get Model Viewer output and I run the legacy NPAR TESTS command with no memory warning.

So you may check your hardware specifications, the SPSS version and which command procedure you use (legacy nonparametric tests or the newer NPTESTS)

Three points:
- If you prefer regular pivot table output, you can get that from NPTESTS by going to Edit > Options > Output and changing the Output Display setting

If you are using weights, the NPAR TESTS procedure will replicate cases according to the weight values. This can greatly increase the memory usage, so scaling the weights down would reduce the memory requirement.

Of course, you can follow the suggestion in the message and increase the SPSS workspace size.